While I'm rhapsodizing about unreliable analog effects, let's take a moment to reflect on the humble DOD FX25B Envelope Filter.
(I had to recolor this one to be green in order to match the physical pedal. For some reason, DOD's image is blue. This is not the worst sin committed by DOD's website--among other things, it sorts the pedal lines into categories like "Wrath of DOD" and "DOD is Love." Also, they have a Yngwie J. Malmsteen signature pedal, which I believe is actually considered a dangerous munition for the purposes of export.)
Put it this way: the FX25B lives up to DOD's hard-earned reputation as a builder of cheap, oddly-designed, unsubtle effects pedals*. The "blend" knob (added as a nod to the bassists who mostly bought the original unit, hence the "B" in FX25B) is not really a blend so much as a dry signal cut--keep it at 9 o'clock if you want any bass at all. The sensitivity is, sorry to say, way too sensitive, and usually has only one useful position, which (for me) is about 98% of the pot's available throw, and has to be precisely tweaked. Oh, and best of all, activating the pedal causes a volume drop of 20%, give or take.
And yet, with all those caveats, I always come back to this little green monstrosity whenever I want an envelope filter, because I can't get anything that will quack in quite the same touchy, uneven, delightful way. I've tried using Boss autowahs, a Bass crybaby, a regular wah, Digitech's bass synth, every Mu-Tron and generic envelope emulation in the Pod, and a gaggle of squawking VST effects--none of them give me the sound in my head as well as the FX25B. Not bad for a pedal that goes for ~$15 on eBay.
Little effects pedals like this are often called stompboxes, for the simple reason that they're metal boxes that you stomp on to activate them. But I love the word stompbox because it really sounds like something a little garish or unrestrained, and I myself am not a restrained effects consumer. It's like in every multi-FX unit review, the writer invariably calls the presets "showy" and "extreme"--I'm the guy who thinks those presets are awesome, and keeps them around just in case. It goes to show how individual sound choice can be, and why a pedal that can seem as profoundly silly as the DOD Envelope Filter is nonetheless one of my favorite stompboxes from my collection.
Or maybe there's just no accounting for taste.
* A quick key to the range of mainstream pedal manufacturers: if you want uninspired but reliable sounds, buy Boss. If you want incredibly cheap, flimsy, over-the-top crap, get one of those plastic Danelectro units. If you can't make up your mind between the two, you're a potential DOD customer.